Liquid applicator



Jan. 30, 1968 H. s. MULL LIQUID APPLIOATOR Filed Nov. 30. 1965 I N VEN TOR. Home 9. M04.

United States Patent 3,366,091 LIQUID APPLICATOR Homer S. Mull, Lancaster, Ohio, assignor to Anchor Hocking Glass Corporation, Lancaster, Ohio, a corporation of Delaware Filed Nov. 30, 1965, Ser. No. 510,649 2 Claims. (Cl. 118-259) ABSTRACT OF THE DISCLOSURE A liquid adhesive applicator of the type wherein adhesive is transferred to the rims of moving product filled containers from an adhesive reservoir by the use of a rotating adhesive applying roller. A plate is positioned in the liquid adhesive within the reservoir so that it extends from a position spaced slightly from the roller to a position spaced slightly from the opposite side of the reservoir. The plate is positioned below the adhesive surface and above the reservoir bottom for forming an adhesive flow directing means which cooperates with the turning roller to continually circulate all of the adhesive within the reservoir. The plate thereby minimizes any adverse effects of a product such as powdered food which may be carried from the filled containers to the adhesive by the roller by preventing a build-up of the powder or other contaminant at the roller.

The present invention relates to an improved liquid applicator and more particularly to an improved roller mechanism and cooperating liquid reservoir for applying liquid coatings such as adhesives or the like. Thin liquid coatings are now applied to the surfaces of moving articles 'by roller applicators which apply a thin liquid coating to the article surface by transferring the liquid from an associated reservoir.

An important liquid applicator of this type, for example, is an adhesive applicator such as is used in the packaging industry for applying adhesive coatings to the rims of containers. A layer of adhesive is applied to the container rims after the containers have been filled to affix a sealing membrane across the container mouth such as air-tight safety seal membranes.

Liquid applicators of this type are shown, for example, in United States Patents Nos. 2,952,239 and 3,038,145 owned by the assignee of the present invention. Such applicators include a rotatably mounted roller adapted to receive a thin layer of adhesive from a liquid reservoir mounted at the roller and having an open side to permit passage of liquid adhesive onto the revolving roller which in turn transfers the adhesive to the tops of containers passing beneath the roller.

The present invention is an improvement in liquid applicators of this general type which is particularly useful for applicators being used to apply adhesive to containers filled with powdered contents. One such product which is usually sealed in containers having a safety seal membrane adhered to the container rim is powdered coffee. In all cases Where such fluid applicators are used it is important that the adhesive film as applied by the roller is of a predetermined thickness and uniformly distributed to provide a completely air-tight seal entirely around the container rim. One feature contributing adversely to this result is the presence of impurities in the liquid adhesive itself. While such impurities may be initially present in the adhesive or pass into the adhesive in the applicator reservoir during its use in one way or another, a principal contributor of contamination when powdered products are being sealed results from the transfer of the powder from the container to the adhesive film on the roller and thence into the reservoir.

3,3653% Patented Jan. 30, 1968 While the presence of a small amount of powder or other impurities would not normally interfere significantly with the adhesive application or the membrane sealing, it has been found that even relatively small amounts of such contaminants present a serious problem since the contaminants tend to move to the open end of the reservoir adjacent the roller and to collect or form into larger coagulated particles which quickly increase in size to the point where they interfere with the passage of fluid to the roller and interfere with the passage of the adhesive to the roller and container surfaces.

As indicated above, the adhesive applying operation on container rims requires a metering of the adhesive onto the roller surface in a film of predetermined thickness and the operation is performed by changing the spacing of the straight edge of the adhesive reservoir or a suitable doctor blade. The presence of the coagulated groups of contaminants at or near the blade interferes with this metering operation.

The improvement of the present invention eliminates this bunching or coagulating of impurities by causing the impurities to be uniformly distributed throughout the adhesive reservoir in which condition their adverse effects are eliminated.

Accordingly an object of the present invention is to provide an improved method and means for applying adhesive films.

Another object of the present invention is to provide an improved means for applying adhesive films to container rims.

Another object of the present invention is to provide an improved method and means for circulating adhesive in an adhesive applying reservoir.

Another object of the present invention is to provide a relatively simple and stationary mechanism for circulating adhesive in the reservoir of a roller type adhesive applicator.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a perspective View partially cut away of a liquid applicator in accordance with the present invention;

FIG. 2 is a top plan view of the liquid applicator of FIG. 1; and

FIG. 3 is a vertical sectional view taken along line 3-3 on FIG. 2.

The liquid applicator 1 includes a reservoir 2 for the adhesive 3 being applied and an adhesive applying roller 4 rotatably mounted adjacent the reservoir 2 with its surface 5 positioned as illustrated in FIG. 3 adjacent the open end 6 of the reservoir 2 and slightly spaced from a straight lower edge 7 of the reservoir 2 which acts as a metering edge to determine the thickness of the adhesive 3 being drawn from the reservoir 2 onto the surface 5 of the turning roller 4. In the embodiment of the applicator 1 illustrated, the roller 4 is rotatably mounted on a suitable shaft 8 held in bearings 9 on a frame 10.

The reservoir 2 is slidably supported on suitable flanges 11 provided on the frame 10 with the lower adhesive metering edge 7 of the reservoir 2 adjustably positioned with respect to the roller surface 5 by means of a threaded reservoir positioning screw 12. With the above construction and as best illustrated in FIG. 3, it is seen that the liquid adhesive flows against the roller surface at the open end 6 of the reservoir and that the film of the contacting adhesive is drawn onto the moving surface of the roller 4 and is carried downwardly into engagement with the top of a moving container 13. The thickness of this film is determined by the distance between the roller surface 5 and the reservoir edge 7.

In the preferred embodiment of the invention, a relatively thin plate-like member is supported above the reservoir bottom 16 by spacers 17 and an anchoring bolt 18. This plate has a relatively straight front edge 19 spaced a short distance from the roller surface 5 and a rear edge 20 spaced a short distance from the reservoir back wall 21. The spacing of the plate 15 from the roller 5 is not critical but is made sufiiciently great to assure clearance between the roller 4 including product particles thereon and the plate edge 19. The spacing of the rear edge 20 of the plate 15 is made at least several times the thickness of the adhesive film on the roller 4 or greater to permit a free passage of adhesive 3 around this edge 20 in the flow controlling operation of the plate 15 which will now be described. As described above the plate edges 19 and 20 are spaced from the roller 4 and the back wall 21 of the reservoir 2 respectively and a preferred relative spacing is illustrated in FIG. 3 wherein edge 19 of the plate 15 is closer to the roller 4 than the edge 20 of plate 15 is to reservoir wall 21 thereby necessarily causing a higher velocity of adhesive flow in the zone of the plate edge 19 than at the back of the reservoir thereby tending to cause any accumulation of particles to occur in the lower velocity zone well away from the metering edge 7.

As indicated above, prior reservoirs were objectionable in certain uses due to the concentration or bunching of impurities in the adhesive adjacent the surface 5 of the roller 4 and at the lower edge 7 of the reservoir so that these collected impurities interfered with the passage of the adhesive 3 onto the roller surface 5 and also passed onto the container rims to interfere with the gluing operation. The above described plate member 15 provides for a circulation of the adhesive 3 within the reservoir to provide a generally clockwise flow pattern (FIG. 3) of adhesive away from the roller 4 on the top of the plate 15 and towards the roller 4 beneath the plate 15 so that the entire supply of adhesive within the reservoir is continuously circulated whereby any contaminants present including powdered matter such as powdered coffee are uniformly distributed throughout the adhesive and so that the concentration of impurities at any point within the liquid adhesive is so low as to be of negligible effect.

While the plate member 15 shown in a preferred embodiment is supported on spacer members 17, it is clear that a variety of other mountings may be used to position the plate in the approximate position illustrated to obtain the circulating effect. The distance of the plate above the reservoir bottom is not critical, however, good results are obtained with a plate spaced above the reservoir bottom at a distance of at least several thicknesses of the adhesive film thickness on the roller or even a greater height. As illustrated in FIG. 3, the reservoir bottom wall 16 is thickened adjacent the metering edge 7 and this thickening plus the presence of the adjacent spacer 17 forms a reduced volume fiow zone for the circulating adhesive in this zone insuring a slightly faster adhesive flow further resisting particle accumulation.

It is preferable that the plate 15 be spaced sufficently close to the bottom of the reservoir so that its upper surface be covered at all times by adhesive even with a reduced adhesive supply in the particular coating operation being performed so that the adhesive circulation effect as illustrated in FIG. 3 is maintained. The sides 22 of the plate member 15 are preferably positioned relatively close to the side Walls 23 of the reservoir to assure the above described circulation effect and to thereby prevent the accumulation of contaminant at the roller 4 near the side walls 23 of the reservoir.

It will be seen that the present invention provides for an important improvement for liquid applicators and particularly for those applicators that apply adhesive to containers for powdered materials. The improvement provides for better operation of the applicators through the prevention of build-up of contaminants and is also a relatively simple device easily applied to present applicators for improving their operation both in situations involving powdered material or in any other situation where the adhesive is subject to contamination with dust, dirt, or other particles and particularly where it is impractical to interrupt the adhesive applying operation to clean or replace the liquid adhesive. The invention is of particular value in operations of a continuing type such as with food packaging machines.

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. In an adhesive applicator for applying adhesive to the rim of a moving container filled to a level adjacent the container top with loose particles for the subsequent application of a sealing member to the container rim and having a liquid reservoir with an open end including a relatively straight metering edge and an adhesiveapplying roller rotatably mounted with its surface spaced from the metering edge for receiving a coating of adhesive from the reservoir, the improvement which comprises a flat relatively level bottom on said reservoir, a generally level adhesive flow control plate positioned in said reservoir beneath the surface of the adhesive and a predetermined distance from the bottom of the reservoir, one edge of said plate being positioned adjacent to said roller at the open end of said reservoir forming an adhesive passage wider than the said particles for permitting adhesive flow from the top to the bottom of the reservoir, the opposite end of the plate being positioned adjacent the opposite end of the reservoir and spaced therefrom a distance greater than the width of said adhesive passage at the said one edge of said plate and permitting adhesive flow from the bottom to the top of said reservoir at a lower speed than said flow at said one end of the plate and causing a generally horizontal laminar adhesive flow in said reservoir on opposite sides of said plate intermediate the plate ends and causing a generally uniform distribution of particles in said adhesive and a movement of particles away from the metering edge during rotation of said roller on the container rim.

2. The adhesive application as claimed in claim 1 which further comprises means positioned adjacent said metering edge and beneath said adhesive control plate for reducing the cross-section of the adhesive flow zone rearwardly from the metering edge whereby the adhesive flow velocity is increased in a zone adjacent to the reservoir metering edge.

References Cited UNITED STATES PATENTS 676,237 6/1901 Knowlton 118261 X 2,399,688 5/1946 Metzner et al. 118259 X 2,534,320 12/ 1950 Taylor. 2,762,072 9/1956 Madalinksi 118261 X 2,855,895 10/1958 Burns et al. 118259 X 2,952,239 9/1960 Stover 118-244 3,094,924 6/ 1963 Stark. 3,137,591 6/1964 Schoutisscn 118-259 X CHARLES A. WILLMUTH, Primary Examiner.

ROBERT I. SMITH, Assistant Examiner. 

